This invention relates to a method and apparatus for the cleansing of bodies of water such as swimming pools, reservoirs, dams and the like. In particular, it is directed to the removal of bacteria, microbes and other cell growth from water.
Large bodies of water such as swimming pools, water catchment areas and similar where the water therein is to be in subsequent contact with people (either by swimming or bathing in the body of water, or by drinking the water) requires cleansing. Although various filters incorporating a filtration medium such as sand can be used to remove particulate matter and other solid debris, the removal of harmful bacteria and other microbiological growth is more difficult. Such bacteria and the like are usually removed by regularly dosing the body of water with a suitable chemical. For example, sodium hypochlorite is commonly added to swimming pools to maintain the dissolved chlorine content of the water at a level which is lethal to any bacteria and the like which is present in the water. In municipal works, where a body of water has to be purified to drinking water standards, a large range of chemicals may be added to the water to purify it.
There are a number of disadvantages to these existing methods. Swimming pools usually cannot be used until some period after treatment because the chlorine content necessary to purify the water often irritates the eyes of any person in the pool. In drinking water treatment, there is increasing concern by the community that the deliberate addition fo chemicals into the water supply is harmful in itself. for example, it can lead to allergic reactions in some consumers of the treated water. Therefore, for an increasing number of consumers, it is necessary to filter or otherwise further treat the supplied water before it can be used or consumed. Of course, the use of chemicals and/or further treatment of supplied water all ad to the financial costs of maintaining an acceptable supply of water for use by the community.
It is thus a general object of the present invention to overcome, or at least ameliorate, one or more of the above disadvantages.
According to the present invention there is provided a method of for the removal of bacteria, microbes and other cell growth from a body of water, said method comprising:
applying an electromagnetic field to a section of said pipe or similar conduit communicable with the body of water as water passes therethrough, said electromagnetic field having a frequency or a range of frequencies sufficient to inhibit or remove said bacteria, microbes or other cell growth from said water.
The application of the electromagnetic field to said section of pipe can be achieved by magnetizing an element or elements positioned on the wall of the pipe or conduit.
Four equally spaced elements can be placed on the wall of the pipe or conduit.
The elements can be elongate strips of ferrite material.
The ferrite material can be manganese-zinc.
The element can be a magnetizable coil.
According to a further aspect of the present invention there is provided apparatus for the removal of bacteria, microbes and other cell growth from a body of water, said apparatus comprising:
a magnetizable element adapted to be disposed about a section of a pipe communicable with the body of water;
means for applying a signal to said magnetizable element to create an electromagnetic field within said pipe, said electromagnetic field having a frequency or a range of frequencies sufficient to inhibit or remove said bacteria, microbes or other cell growth from said water.
The magnetizable element can comprise one or more ferrite elements placed on the wall of the section of pipe.
The one or more ferrite elements can be manganese-zinc elements.
The magnetizable element can be a coil for application of the electromagnetic field to the pipe or conduit the coil being wound about a polyvinyl chloride (PVC) or other non-ferrous former which is located coaxially about the pipe or conduit.
An AC voltage can be applied to the magnetizable element to generate the electromagnetic field.
The voltage can be 5 volts AC.
The frequency of the voltage applied to the magnetizable element can vary to sweep a range of frequencies in the range of 2 KHz to 7 KHz.
The signal applied to the magnetizable element can be in the form of a positive going square wave followed by a negative going spike having a variable frequency.
The means for generating the signal can comprise first and second square wave oscillators whereby the output of the second oscillator is modulated in frequency by the output of the first oscillator.
The signal generating means can include a third square wave oscillator whereby the output of the second oscillator is used to frequency modulate the output of the third square wave oscillator.
Amplifier means can be employed for amplifying the output of the third square wave oscillator, the output of the amplifier means is adapted to be connected to the magnetizable element via capacitance means to define the required form of the signal.